This invention relates to an orthopedic appliance and a method for realigning the spine and the femorae when the user is in the prone position. More specifically, this invention relates to an orthopedic appliance having a support device which can recreate the angle made while an individual is standing between a longitudinal axis of the lower lumbar spine and the longitudinal axis of the femorae when the user is lying in the downward facing or prone position.
Illustrated in FIG. 1 is a human body 70, having front side 72 and back side 74, lying lengthwise on a resting surface, bed or the like 5 in a prone position along a longitudinal axis X--X. The internal body structures shown include the sacrum 90, the portion of the spinal column situated along the lowermost five discs in the part of the back between the lowermost ribs and the sacrum and called the lumbar spine 80 and the bones extending from the hip to the knee called the femorae 100. The longitudinal axis of the lower lumbar spine A is defined as the line running through the center portion of the last two discs of the lumbar portion 80 of the spinal column. The longitudinal axis of the femorae B is defined as the line running through the center of the upper slightly curved portions of the femorae 100. The location of the abdominal area containing the stomach, intestines, liver and other visceral organs and the bladder region are known to those in the orthopedic art and, thus, not shown.
The Applicant has concluded from lateral projection X-ray tests that when a sizable percentage of individuals are standing or laying on their back on a firm, substantially planar resting surface, the longitudinal axis of their lower lumbar spine in relation to the longitudinal axis of their femorae is approximately within a range of 120.degree. to 140.degree., as measured about the sides of these axes facing a front side of the individuals. The largest concentration of these individuals have their lower lumbar spine to femorae longitudinal axes form approximately a 130.degree. angle to each other when the individuals are standing or lying on their backs.
As seen in FIG. 1, when an individual 70 is lying in a prone position, even with a relatively good sleeping posture and a firm, substantially planar resting surface 5, a deforming force is caused between the lower lumbar spine 80 and the femorae 100. This deforming force is mainly caused by the weight of the pelvis. This deforming force causes the angular relationship, as viewed from a front side 72 of the individual 70, between the longitudinal axis of the lower lumbar spine A and the longitudinal axis of the femorae B to increase or open out to approximately a parallel or 180.degree. relationship between these two axes as shown in FIG. 1. This change in the femorae and the lower lumbar spine axes position between the standing and the prone position can cause excessive compressive forces on the lower region of the back. Of most concern is the pressure these forces place on the apophyseal joints in the region of the lumbosacral junction. This change in the axes relationship, therefore, can lead to considerable pain of the lower back.
There have been proposed various orthopedic appliances which are directed to maintaining and correcting posture. These appliances, when directed to prone position posture, teach pads of a general rounded structure on the front side of an individual.
U.S. Pat. No. 2,617,412 to Steinberger discloses a pad 7 on the abdomen which may be of a thickness to support the spine in a proper manner while the individual, while sleeping, occupies a prone position in which the size, shape, position and thickness of the pad will depend on the size of the wearer and the corrective measures sought. In Steinberger, the pads, formed of any suitable soft or yieldable substance, possess their maximum thickness in the centers thereof and taper to substantially a feather edge at their outer margins, so as to provide comfort.
U.S. Pat. No. 4,616,639 to Huber discloses an elasticized orthopedic-type belt for obtaining correct anatomical position (i.e., slight lordosis) of the lumbosacral spine while lying prone. Included in Huber are resilient foam anterior pads 28 and 30 to provide support under the anterior superior iliac spines when the wearer is lying prone to prevent the pelvis from rolling forward into an anterior pelvic tilt.
U.S. Pat. No. 2,813,526 to Beebe discloses an abdominal pad 28 to overcome sacroiliac slip, i.e., excessive rearward movement about the sacroiliac joint, when an individual is walking. The abdominal pad of Beebe has a lower section with an inward curve.
None of the above mentioned references apparently teach the importance of a biomechanical supporting appliance pad with surfaces at such angles to realign the lower lumbar spine in relation to the femorae to offset the change in relationship of the axes during normal prone sleeping position. Therefore, it is considered an improvement to have an orthopedic appliance to recreate the angle made, while standing, between a longitudinal axis of the lower lumbar spine and a longitudinal axis of the femorae when the user is lying in a prone position.